<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>颜色渐变</title>
		<style type="text/css">
			body{
				width: 300px;
				height: 200px;
				background-image: linear-gradient(transparent,rgba(0,0,0,.5));  /*背景颜色从透明到半黑*/
			}
		</style>
	</head>
	<body>
	</body>
</html>
